Prince of Wales Mine at Harrowbarrow


Heritage Category: Scheduled Monument

List Entry Number: 1021411

Date first listed: 30-Nov-2006


Ordnance survey map of Prince of Wales Mine at Harrowbarrow
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The building or site itself may lie within the boundary of more than one authority.

District: Cornwall (Unitary Authority)

Parish: Calstock

National Grid Reference: SX 40083 70572


Legacy Record - This information may be included in the List Entry Details.

Reasons for Designation

For several millennia the western part of the South West Peninsula, namely Cornwall and West Devon, has been one of the major areas of non-ferrous metal mining in England. It is defined here as prospecting, extraction, ore processing and primary smelting/refining, and its more important and prolific products include copper, tin and arsenic, along with a range of other materials which occur in the same ore bodies. Throughout much of the medieval period most of the tin was extracted from streamworks, whilst the other minerals were derived from relatively shallow openworks or shafts. Geographically, Dartmoor was at the peak of its importance in this early period. During the post-medieval period, with the depletion of surface deposits, streamworking gradually gave way to shaft mining as the companion to openworking methods. Whilst mining technology itself altered little, there were major advances in ore processing and smelting technologies. The 18th century saw technological advances turning to the mining operations themselves. During this period, Cornish-mined copper dominated the market, although it was by then sent out of the region for smelting. The development of steam power for pumping, winding and ore processing in the earlier 19th century saw a rapid increase in scale and depth of mine shafts. As the shallower copper-bearing ores became exhausted, so the mid to late 19th century saw the flourish of tin mining operations, resulting in the characteristic West Cornish mining complex of engine houses and associated structures which is so clearly identifiable around the world. Correspondingly, ore processing increased in scale, resulting in extensive dressing floors and mills by late in the 19th century. Technological innovation is especially characteristic of both mining and processing towards the end of the century. In West Cornwall, these innovations relate chiefly to tin production, in East Cornwall and West Devon to copper. Arsenic extraction also evolved rapidly during the 19th century, adding a further range of distinctive processing and refining components at some mines; the South West became the world's main producer in the late 19th century. From the 1860s, the South West mining industries began to decline due to competition with cheaper sources of copper and tin ore from overseas, leading to a major economic collapse and widespread mine closures in the 1880s, although limited ore-extraction and spoil reprocessing continued into the 20th century. A sample of the better preserved sites, illustrating the technological and chronological range, as well as regional variations, of non-ferrous metal mining and processing sites, together with rare individual component features, are considered to merit protection.

The northern part of the Prince of Wales Mine at Harrowbarrow survives well and contains an extensive range of structures associated with a late 19th century tin mine. The dumps in particular form a prominent local landmark and will contain information concerning the character and efficiency of tin extraction. The mine has a long history and much of it is represented by the surviving structures.


Legacy Record - This information may be included in the List Entry Details.


The monument includes the northern part of the Prince of Wales Mine which is situated on a gentle south facing slope on the northern edge of Harrowbarrow village. The mine represents an amalgamation of several other mines amongst which are Wheal Fortune, Wheal Pleasant, Wheal George, Wheal Barnard and West Edward which together were known as Calstock United Tin and Copper Mines in the early part of the 19th century. In 1861 the mine was re-constituted as the Prince of Wales Mine and operated intermittently from then until 1914. In 1940, during World War II, a processing floor was established at the mine to rework the earlier dumps and material from nearby small mines and Devon Great Consols. In about 1971 a Canadian company carried out exploratory work including drilling and finally in 1977 an exploratory adit was cut into the hillside. Between 1861 and 1914 output from the mine was 10,845 tons of copper ore, over 1000 tons of black tin and 7,720 tons of arsenic yielding iron pyrites. The mine's relatively long and productive life has resulted in a complex series of structures and earthworks surviving. Amongst these are three engine houses, shafts, a dry, at least two processing floors of different dates, a magazine, two boiler ponds, tramways, concrete buildings and extensive waste dumps. All three engine houses were constructed with pinkish shillety killas, with wooden lintels and without granite quoining. The western engine house was built in 1888 and powered stamping machinery. It was modified during the 1940's reprocessing event and at this time the stamping floor, loading and boiler house were demolished. The middle engine house, built in 1879, once held a 50 inch pumping engine extracting water from the adjacent Watson's Shaft and its boiler house is attached to its eastern wall. Its detached chimney, which is capped with brick and incorporates a decorative drip-ring and cap, stands a short distance to the north west and they are connected to each other by an underground flue. The third engine house, installed in 1888, held an all-indoor beamed rotative engine for winding from Watson's Shaft. The bedstone remains in its original position and to the south is the crankshaft loading and a rectangular pit which would have held the winch drum. Traces of the boiler house survive to the north. The dry building stands to the north of the pumping engine house and was enlarged to incorporate its chimney sometime between 1881 and 1906. In this building miners' wet clothing was dried, presumably using heat generated by a flue from the nearby boiler house. Much of the earlier tin dressing floor now underlies later waste material, although three conical buddles protruding through this material indicates that much of this floor, which was housed in a large building, survives as a buried feature. By contrast much of the 1940's dressing floor survives as a series of concrete footings and bases together with a large ore bin. A small stone-built standing structure set away from the mine at NGR SX 39957059 may represent the site of a powder magazine. Two boiler ponds are known from early maps. The first at NGR SX 40027058 has been truncated by the 1977 adit, whilst the other larger example at NGR SX 40107063 survives as a rectangular water filled hollow denoted on its lower side by a substantial bank. A small number of concrete buildings surviving within the monument relate to the 1940's reworking, whilst a large adit together with tramways belong to the 1977 exploration. Dominating the southern part of the monument are substantial dumps of fine yellow-grey sand. These represent waste from the 1940's activity, but they do overlie and protect earlier dumps. Modern fences built around open shafts and other structures are excluded from the scheduling, but the ground beneath them is included.

MAP EXTRACT The site of the monument is shown on the attached map extract.


The contents of this record have been generated from a legacy data system.

Legacy System number: 36035

Legacy System: RSM


Books and journals
Sharpe, A, Duchy of Cornwall Industrial Sites: A Survey, (1989), 10-22

End of official listing